Long Distance

Units at long distance will receive damage but attacks may miss units at closer range.

Cats and enemies with this ability are able to attack at uber long distance and even hit enemies outside their attack range (since the majority of these units have area attacks), but cannot harm any unit that is close enough to them, rendering them virtually unable to damage anyone close unless said unit is knocked back into their range again.

Initial Abilities

Strong Against

Indicated enemy types will take extra damage with damage received from that type also reduced.

One of the more commonly-seen abilities within the cat units. Units with this ability will deal 1.5x and take 0.5 damage from said enemy, which could be White, Floating, Red, Black, Angel, Alien, or Zombie type. The Fruit Treasures increase the effect of this ability against certain enemy types to 1.8 damage dealt and 0.4x damage.

Resistant

Damage received from indicated enemy types will be reduced significantly.

Cat Units with this ability take only 1/4 of an enemy's total damage, making them extremely durable against the type of enemy listed. The Fruit Treasures will increase the effect against certain enemy types to taking 1/5 of an enemy's total damage. Units with the Resistant ability usually have enormous HP pools.

Knockback

Unit has a set chance to push indicated enemy types back towards their base.

Some cats and enemies have this ability; the default Cat Cannon also has this effect, but on a smaller scale (the knockback isn't as long as the unit ability). Cat units with this ability can push a specific type or all enemies back regardless of damage dealt, while enemy units with this ability can push back all cat units. This ability usually only activates a set percentage of the time, varying between Cats, with the knockback range varying as well. Units with only 1 knockback (such as Tank Cat) can still be knocked back by this ability. The Fruit Treasures increase the knockback distance, as well as any Cat Combos affecting knockback.

Slow

Indicated enemy types will have their speed reduced for a set amount of time.

Some cats and enemies have this ability. Any units with this ability can slow the other side's units from advancing the battlefield, and units affected will move at the speed value of 1 temporarily. (AKA 15 range per second) (The speed of the slow is universally the same.) The Fruit Treasures increase the duration of this effect against certain enemy types by 20%.

Freeze

Indicated enemy types will become unable to move for a set amount of time.

Some cats and enemies can have this ability. Any units with this ability can stop the other side's units from advancing the battlefield. Units affected by the effect will be frozen for period of the time and any attack animation will be halted. This ability depends on the success chance and the duration of the effect varies between units. The Fruit Treasures increase the duration of this effect against certain enemy types by 20%.

Critical

Attacks by this unit have a set chance of extra damage that can hurt Metal enemies.

Cats or enemies with this ability can sometimes do a Critical Hit. Critical Hits ignore a Metal enemy's (or your Metal Cat's) ability of taking the "one hit = 1 damage" and inflict two times the damage, regardless of enemy type.

Wave Attack

Attacks will strike all enemies in range delivering extra damage from the energy wave released.

Cats or enemies with this ability can sometimes create Shockwaves, but only when their attack connects with a unit. The number of waves depends on the unit's ability level while the damage is equal to a normal attack. Shockwaves do not inflict damage to either side's base.

Units with the "Unharmed by Waves" ability ignore Shockwaves. Units with the "Wave Blocker" ability ignore Shockwaves and prevent them from harming any cats behind the unit.

After BCJP 4.0

Into the Future was added along with those abilities.

Strengthen

After this unit's health falls below a set amount its attacks grow much stronger.

Units with this ability can increase their own attack power. This ability is triggered when the unit reaches a certain amount of health (see Ursamajor or Mistress Celeboodle, and Akira) The duration may vary; it can last for a short duration or as a permanent effect.

Weaken

Indicated enemy types will have their attack power reduced for a set period.

Cats and enemies with this ability have a chance to decrease an enemy's base damage or a cat unit's base damage, respectively. Effectiveness and duration vary from unit to unit. The Fruit Treasures increase the duration of this effect against certain types of enemies by 10%.

Survive

After this unit's health falls below zero it may heal itself by a small amount.

Cats or enemies with this ability can sometimes survive a lethal strike based on a percentage chance. Instead of dying, they are knocked back with 1 HP left. Some cats with this ability are Mer-Cat, Kai, Pogo Cat, Allen O' Neil and Surfer Cat.

Unharmed by Waves

This unit does not take damage from Wave attacks.

Shockwave damage is completely ignored by this ability. When hit by a Shockwave attack, units with this ability will briefly have a small blue shield icon appear beside them, indicating that they have taken no damage from the Shockwave.

Resist Knockback

This ability was added since BCJP 5.3

Enemy attacks will not cause this unit to be knocked back.

Cats with this ability will be immune to knockback from enemies with the knockback ability, such as Super Metal Hippoe. They can still be knocked back from having their health fall below a certain amount. Upon being hit with an attack that normally inflicts knockback, cats with this ability will briefly display a blue barrier in front of them to indicate that the effect had been negated.

For a full list of cats with the "Resist Knockback" ability, see here.

Resist Slow

This ability was added since BCJP 5.3

Enemy attacks will not cause slowdown against this unit.

Cats with this ability are immune to being slowed down by enemy attacks that cause slowness, like Sunfish Jones. Upon being hit with a slowing attack, cats with this ability will briefly display a blue barrier in front of them to indicate that the effect had been negated.

Resist Freeze

This ability was added since BCJP 5.3

Enemy attack will not freeze the movement of this unit.

Cats with this ability are immune to being Frozen by enemies, such as Maawth. Upon being hit with a freezing attack, cats with this ability will briefly display a blue barrier in front of them to indicate that the effect had been negated.

Resist Weaken

This ability was added since BCJP 5.3

Enemy attacks will not weaken the attacks of this unit.

Cats with this ability are immune to being weakened by enemy attacks that weaken attack power, like Calamary. Upon being hit with a weakening attack, cats with this ability will briefly display a blue barrier in front of them to indicate that the effect had been negated.

Wave Shield

This ability was added since BCJP 5.7

This unit can negate Wave Attacks and protect units behind them from their effect.

Cats with this ability are not only immune to all Shockwave damage but will also cancel the Shockwave on contact. Any unit behind the Wave Blocker will not be harmed by the Shockwave. Upon being hit with a Shockwave, Cats with this ability will briefly display a clear hexagonal barrier in front of them to indicate that the wave had been cancelled.

Zombie Killer

This ability was added since BCJP 5.7

Units with this ability can prevent Zombie enemies from reviving.

A Zombie won't revive if a Zombie Killer does the final blow, which is signified by a blue flash as well as a unique sound effect. Many anti-Zombie cats have this ability, which is best used against Zombies that revive many times.

After BCJP 6.5

Warp

An ability exclusive to enemies. Depend on the success chance and attack type of the enemy, one or a group of Cats got hit will be warped back a specific distance and in a specific amount of time. Warp distance and warp time is varied to enemies, currently (6.8) the Star Peng has the longest abduct time (100f>10f) and Mystic Mask Yulala has the longest warp distance (1500>250).

Trivia

The portals created by 'Starred' Aliens resemble the portals from the game Portal as the initial portal is orange while the secondary portal is blue.

Warp Blocker

Units with this ability aren't affected by enemy Warp abilities.

An ability some cat units have to deal with the enemies' Warp ability. Those Cats will ignore all warp effects. Upon being hit with a warping attack, Cats with this ability will briefly display a blue barrier in front of them to indicate that the effect had been negated.

Barrier

This ability is exclusive to enemies. As its name suggests, enemies with this ability are protected by an invincible red shield that blocks all attacks that are weaker than its limit. The player needs to do one attack with high enough power to break it, which is the upper limit it can protect the enemy. An animation of the barrier materializing and flashing is shown when an attack of insufficient strength hits the barrier, and another one of the barrier cracking and falling apart when it breaks. When a barrier is destroyed, excess damage the killing blow would have dealt is completely negated.
Attacks of insufficient strength cannot inflict knockback or debuffs upon enemies that have their barriers up.

Each enemy with this trait has a different barrier limit, currently (6.8), the Youcan has the toughest barrier (265000>40000). Critical Hits do not affect much since the barrier require raw damage to break it. It does include "Massive Damage" and "Strong Against" effects during damage calculation. Cats with the Barrier Breaker ability will help a lot against this trait.

Barrier Breaker

Units with this ability can nullify enemy barriers and deliver huge damage upon break.

The counter ability of Barrier. Cats with this ability can break all barriers, even the ones that their raw attack power at level cap can't reach. This is indicated by a unique animation where the barrier shatters violently as opposed to cracking apart when normally destroyed. If a Barrier Breaker unit manages to break a barrier, the attack that destroyed the barrier will deal full damage to the enemy. However, there is a success chance to break a barrier. Some Cats have 100% chance to break barriers, like God-Emperor Dioramos. Loincloth Cat is a good option.